1. Field of the Invention
The present invention relates to the dehydrocyanation of aliphatic dinitriles in the vapor phase, and, more especially, to the dehydrocyanation of branched saturated aliphatic dinitriles. Such dinitriles are often byproducts having little value emanating from the production of linear saturated dinitriles. The dehydrocyanation of such compounds produces ethylenic nitriles which are useful starting materials in processes for the synthesis of linear dinitriles.
2. Description of the Prior Art
U.S. Pat. No. 3,795,694 describes the production of 1,4-dicyanobutene and 2-methyleneglutaronitrile by dehydrocyanation, typically in liquid phase, of 1,2,4-tricyanobutane in the presence of a basic catalyst. This '694 patent also describes the conversion of 2-methyleneglutaronitrile into 1,4-dicyanobutene by means of hydrocyanic acid in the presence of a basic catalyst.
Such a process is not applicable to the saturated branched aliphatic dinitriles, which are byproducts produced in significant amounts and which are currently generally destroyed.